image.clearRect()
Clears the specified rectangle by filling it with the background color of the current drawing surface.
image.clearRect( x=number, y=number, width=number, height=number )
Returns: Image
Examples
imgRect = imageRead("https://pbs.twimg.com/profile_images/1037639083135250433/fREb9ZhM_400x400.jpg");
imgRect.clearrect(250,150,70,80);
cfimage (action="writeToBrowser" source=imgRect);